>>27
1000 INPUT N
1010 DIM A(N)
1015 PRINT 2
1020 FOR I=3 TO N STEP 2
1030 IF A(I)=0 THEN GOSUB 1060
1040 NEXT I
1050 END
1060 PRINT I
1070 J=3
1080 IF J*I>N THEN RETURN
1090 A(J*I)=1
1100 J=J+2
1110 GOTO 1080